/**

 @Name : layui.laypage 分页组件
 @Author：贤心
 @License：MIT

 */

layui.define(function(exports){
    "use strict";

    var doc = document
        ,id = 'getElementById'
        ,tag = 'getElementsByTagName'

        //字符常量
        ,MOD_NAME = 'laypage', DISABLED = 'layui-disabled'

        //构造器
        ,Class = function(options){
            var that = this;
            that.config = options || {};
            that.config.index = ++laypage.index;
            that.render(true);
        };

    //判断传入的容器类型
    Class.prototype.type = function(){
        var config = this.config;
        if(typeof config.elem === 'object'){
            return config.elem.length === undefined ? 2 : 3;
        }
    };

    //分页视图
    Class.prototype.view = function(){
        var that = this
            ,config = that.config;

        //排版
        config.layout = typeof config.layout === 'object'
            ? config.layout
            : ['prev', 'page', 'next'];

        config.count = config.count|0; //数据总数
        config.curr = (config.curr|0) || 1; //当前页
        config.groups = (config.groups|0) || 5; //连续页码个数

        //每页条数的选择项
        config.limits = typeof config.limits === 'object'
            ? config.limits
            : [5,10, 20, 30,50,100];
        config.limit = (config.limit|0) || 10; //默认条数

        //总页数
        config.pages = Math.ceil(config.count/config.limit) || 1;

        //当前页不能超过总页数
        if(config.curr > config.pages){
            config.curr = config.pages;
        }

        //连续分页个数不能低于0且不能大于总页数
        if(config.groups < 0){
            config.groups = 0
        } else if (config.groups > config.pages){
            config.groups = config.pages;
        }

        config.prev = 'prev' in config ? config.prev : '&#x4E0A;&#x4E00;&#x9875;'; //上一页文本
        config.next = 'next' in config ? config.next : '&#x4E0B;&#x4E00;&#x9875;'; //下一页文本

        //计算当前组
        var index = config.pages > config.groups
                ? Math.ceil( (config.curr + (config.groups > 1 ? 1 : 0)) / (config.groups > 0 ? config.groups : 1) )
                : 1

            //试图片段
            ,views = {
                //上一页
                prev: function(){
                    return config.prev
                        ? '<a href="javascript:;" class="layui-laypage-prev'+ (config.curr == 1 ? (' ' + DISABLED) : '') +'" data-page="'+ (config.curr - 1) +'">'+ config.prev +'</a>'
                        : '';
                }()

                //页码
                ,page: function(){
                    var pager = [];

                    //数据量为0时，不输出页码
                    if(config.count < 1){
                        return '';
                    }

                    //首页
                    if(index > 1 && config.first !== false && config.groups !== 0){
                        pager.push('<a href="javascript:;" class="layui-laypage-first" data-page="1"  title="&#x9996;&#x9875;">'+ (config.first || 1) +'</a>');
                    }

                    //计算当前页码组的起始页
                    var halve = Math.floor((config.groups-1)/2) //页码数等分
                        ,start = index > 1 ? config.curr - halve : 1
                        ,end = index > 1 ? (function(){
                        var max = config.curr + (config.groups - halve - 1);
                        return max > config.pages ? config.pages : max;
                    }()) : config.groups;

                    //防止最后一组出现“不规定”的连续页码数
                    if(end - start < config.groups - 1){
                        start = end - config.groups + 1;
                    }

                    //输出左分割符
                    if(config.first !== false && start > 2){
                        pager.push('<span class="layui-laypage-spr">&#x2026;</span>')
                    }

                    //输出连续页码
                    for(; start <= end; start++){
                        if(start === config.curr){
                            //当前页
                            pager.push('<span class="layui-laypage-curr"><em class="layui-laypage-em" '+ (/^#/.test(config.theme) ? 'style="background-color:'+ config.theme +';"' : '') +'></em><em>'+ start +'</em></span>');
                        } else {
                            pager.push('<a href="javascript:;" data-page="'+ start +'">'+ start +'</a>');
                        }
                    }

                    //输出输出右分隔符 & 末页
                    if(config.pages > config.groups && config.pages > end && config.last !== false){
                        if(end + 1 < config.pages){
                            pager.push('<span class="layui-laypage-spr">&#x2026;</span>');
                        }
                        if(config.groups !== 0){
                            pager.push('<a href="javascript:;" class="layui-laypage-last" title="&#x5C3E;&#x9875;"  data-page="'+ config.pages +'">'+ (config.last || config.pages) +'</a>');
                        }
                    }

                    return pager.join('');
                }()

                //下一页
                ,next: function(){
                    return config.next
                        ? '<a href="javascript:;" class="layui-laypage-next'+ (config.curr == config.pages ? (' ' + DISABLED) : '') +'" data-page="'+ (config.curr + 1) +'">'+ config.next +'</a>'
                        : '';
                }()

                //数据总数
                ,count: '<span class="layui-laypage-count">共 '+ config.count +' 条</span>'

                //每页条数
                ,limit: function(){
                    var options = ['<span class="layui-laypage-limits"><select lay-ignore>'];
                    layui.each(config.limits, function(index, item){
                        options.push(
                            '<option value="'+ item +'"'
                            +(item === config.limit ? 'selected' : '')
                            +'>'+ item +' 条/页</option>'
                        );
                    });
                    return options.join('') +'</select></span>';
                }()

                //跳页区域
                ,skip: function(){
                    return ['<span class="layui-laypage-skip">&#x5230;&#x7B2C;'
                        ,'<input type="text" min="1" value="'+ config.curr +'" class="layui-input">'
                        ,'&#x9875;<button type="button" class="layui-laypage-btn">&#x786e;&#x5b9a;</button>'
                        ,'</span>'].join('');
                }()
            };

        return ['<div class="layui-box layui-laypage layui-laypage-'+ (config.theme ? (
            /^#/.test(config.theme) ? 'molv' : config.theme
        ) : 'default') +'" id="layui-laypage-'+ config.index +'">'
            ,function(){
                var plate = [];
                layui.each(config.layout, function(index, item){
                    if(views[item]){
                        plate.push(views[item])
                    }
                });
                return plate.join('');
            }()
            ,'</div>'].join('');
    };

    //跳页的回调
    Class.prototype.jump = function(elem, isskip){
        if(!elem) return;
        var that = this
            ,config = that.config
            ,childs = elem.children
            ,btn = elem[tag]('button')[0]
            ,input = elem[tag]('input')[0]
            ,select = elem[tag]('select')[0]
            ,skip = function(){
            var curr = input.value.replace(/\s|\D/g, '')|0;
            if(curr){
                config.curr = curr;
                that.render();
            }
        };

        if(isskip) return skip();

        //页码
        for(var i = 0, len = childs.length; i < len; i++){
            if(childs[i].nodeName.toLowerCase() === 'a'){
                laypage.on(childs[i], 'click', function(){
                    var curr = this.getAttribute('data-page')|0;
                    if(curr < 1 || curr > config.pages) return;
                    config.curr = curr;
                    that.render();
                });
            }
        }

        //条数
        if(select){
            laypage.on(select, 'change', function(){
                var value = this.value;
                if(config.curr*value > config.count){
                    config.curr = Math.ceil(config.count/value);
                }
                config.limit = value;
                that.render();
            });
        }

        //确定
        if(btn){
            laypage.on(btn, 'click', function(){
                skip();
            });
        }
    };

    //输入页数字控制
    Class.prototype.skip = function(elem){
        if(!elem) return;
        var that = this, input = elem[tag]('input')[0];
        if(!input) return;
        laypage.on(input, 'keyup', function(e){
            var value = this.value
                ,keyCode = e.keyCode;
            if(/^(37|38|39|40)$/.test(keyCode)) return;
            if(/\D/.test(value)){
                this.value = value.replace(/\D/, '');
            }
            if(keyCode === 13){
                that.jump(elem, true)
            }
        });
    };

    //渲染分页
    Class.prototype.render = function(load){
        var that = this
            ,config = that.config
            ,type = that.type()
            ,view = that.view();

        if(type === 2){
            config.elem && (config.elem.innerHTML = view);
        } else if(type === 3){
            config.elem.html(view);
        } else {
            if(doc[id](config.elem)){
                doc[id](config.elem).innerHTML = view;
            }
        }

        config.jump && config.jump(config, load);

        var elem = doc[id]('layui-laypage-' + config.index);
        that.jump(elem);

        if(config.hash && !load){
            location.hash = '!'+ config.hash +'='+ config.curr;
        }

        that.skip(elem);
    };

    //外部接口
    var laypage = {
        //分页渲染
        render: function(options){
            var o = new Class(options);
            return o.index;
        }
        ,index: layui.laypage ? (layui.laypage.index + 10000) : 0
        ,on: function(elem, even, fn){
            elem.attachEvent ? elem.attachEvent('on'+ even, function(e){
                fn.call(elem, e); //for ie
            }) : elem.addEventListener(even, fn, false);
            return this;
        }
    }

    exports(MOD_NAME, laypage);
});